1. Field of the Invention
The present invention relates to organic electroluminescent devices (also known as organic EL devices) and display devices, particularly to organic electroluminescent devices and display devices that include a thin electrode of inorganic material protected by a conductive organic material.
2. Description of the Related Art
Organic electroluminescent devices (also known as organic EL devices) utilizing the electroluminescence (hereinafter, “EL”) of organic materials are structured to include a stacked organic emission functional layer of an organic hole transport layer and an organic emissive layer between the anode and cathode. Such organic electroluminescent devices are of interest as light-emitting devices capable of emitting bright light by low-voltage DC driving.
In such organic electroluminescent devices, it has been proposed to stack a conductive organic film on the cathode or anode to complement conductivity of the cathode or anode, for which inorganic transparent conductive films such as ITO and IZO, or extremely thin metallic material films are used. As an example, polyethylenedioxythiophene (PEDOT) is used as the stacked conductive organic film (see JP-A-2005-235585)
Further, in the organic electroluminescent device, it has been proposed to stack an organic capping film on one of the anode and cathode disposed on the opposite side from the substrate, in order to prevent degradation of organic material due to moisture penetration. The organic capping film is formed using allylene diamine derivatives, triamine derivatives, CBP, and an aluminum-quinolinol complex (Alq3) (see JP-A-2006-156390).